A

Andy_RR

Well Known Member
I've been thinking about how best to install my newly acquired 2" HID lamps for landing and taxi.

Initially I was going to place both in one wingtip, one as landing and the other as taxi (RV-8). Then I began dreaming about retractable lights. My latest brainwave is to mount the lamps in the bottom surface of the flaps, such that on a flapped final approach they are angled for useful illumination. For taxi purposes, one just need retract the flaps to provide the required illumination.

I can see a few flaws here, but I'm wondering if they are showstoppers.

- you don't have lights on a flapless landing
- you can't use them for recognition lamps
- when you taxi through loose stuff, you'll pepper your flap skins with debris (perhaps)

Also, packaging might be a bit tight but I think I can make it work, or at least I think it's worth a design study. Before I waste more time on it, what thinks the VAF massive?

Cheers,

Andrew

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I see no good reason to put in a complicated retractable lighting system. You have already pointed out flaws in chosen location.
 
Bravo

I think it's a neat idea. That's what's great about these projects -- do little reasonable things that are unique and cool.

I would make a bracket that holds the light on the inside (as you have it angled in the picture), and then have a clear lens (assuming it won't get too hot with it being so close to the light) to keep the same surface of the flap. In other words, no difference on the exterior of the flap, just a clear lens that is like an access plate.
 
Andy_RR said:
I've been thinking about how best to install my newly acquired 2" HID lamps for landing and taxi.

Initially I was going to place both in one wingtip, one as landing and the other as taxi (RV-8). Then I began dreaming about retractable lights. My latest brainwave is to mount the lamps in the bottom surface of the flaps, such that on a flapped final approach they are angled for useful illumination. For taxi purposes, one just need retract the flaps to provide the required illumination.

I can see a few flaws here, but I'm wondering if they are showstoppers.

- you don't have lights on a flapless landing
- you can't use them for recognition lamps
- when you taxi through loose stuff, you'll pepper your flap skins with debris (perhaps)

Also, packaging might be a bit tight but I think I can make it work, or at least I think it's worth a design study. Before I waste more time on it, what thinks the VAF massive?

Cheers,

Andrew

... photo snipped for brevity ...
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Well, since you are asking for opinions, I will give mine.

While I do like the idea of having the landing lights located at the inboard location, however I really do not think that mounting landing lights in the Flaps is a good idea.

First, I doubt that there is room in the Flaps for the light, the ballast for the light, and the mounting bracket for the lights and ballast within the small volume of the Flaps. Also, please keep in mind, that you will want to provide some way to angle the lights up and down as needed until the optimum angle for landing is achieved.

Second, cutting a hole in the Flaps for the light would weaken the Flaps. However, it may be possible to reinforce the area with some extra material around the edges of the hole.

Third, the only way that the lights would really function as landing lights is with Full Flaps landings. However, I doubt that every landing you make will be with Full Flaps. If the winds are gusty, then you may elect to land with little to no Flaps. Or, if there is a Flap failure, then you not be able to obtain Full Flaps. In either case, your landing lights would not be useful and if you are landing at night during gusty winds and/or you are dealing with a Flap failure problem, then not having the landing lights could be critical.

Fourth, installing such a system would mean that run wiring into the Flaps that could extend and retract as the Flaps are extended and retracted. Sorry, but that sounds like an area that would be prone to failure.

I hope this helps!
 
Flap lights

Hi Andy,
One idea that was easy one of the RV4s we fly with has the lights in the air inlet in the cowling. Do what you like thats what makes the build a great adventure
 
worth a bit of SolidWorks time...

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Assuming 4° wing incidence, 40° flap, 1° beam dip. I haven't accounted for the actual wing angle of attack which will probably improve things a little. I don't know what a typical AoA on short final would be, although I probably could calculate an estimate - my brain starts going fuzzy at that point...

I tried to do an aero bubble to cover the top skin aperture, but my surfacing skills weren't up to the job. More work needed, perhaps.

My next idea is to abandon flap-mounting and go back to a wing leading edge, but couple a servo angle controller fed with atitude data knicked from the Skyview bus. Maybe Dynon will be able to engnineer a programmable PWM signal output to drive the servo directly...?
 
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How about putting them in the nose
of the wheel pants with a clear cover to keep the pant shape?
 
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My main objective...

...is to have them in-cockpit-adjustable so that the landing lights can double as taxi lights, rather than carry the extra weight of a second set of lights for ground operation.
 
Andy_RR said:
...is to have them in-cockpit-adjustable so that the landing lights can double as taxi lights, rather than carry the extra weight of a second set of lights for ground operation.
Click to expand...

OK thanks! I do believe that I understand now.

And if so, then I would suggest having the lights installed in the Leading Edge (as is done using the 'Duckworth' kit) and then working up some sort of cockpit adjustable mounting plate system that allows one to adjust the up/down angle of the light.

I expect that one could develop such a system using something like a control cable (as is done with the Mixture Control) or with an electric servo (as is done with Electric Trim).
 
So lets see! Servo's, gimbles,bellcranks,pushrods,cables, etc., to replace 1 or 2, 75 watt halogen bulbs.
I think there is an engineer that's waiting for a kit to get delivered!:D
 
Milt & Jon,
You 2 moderators are harsh. Leave the poor guy alone.... he's an inventor. Who cares if it weighs a ton and will probably break on the first flight. Let him figure it out and his next invention might be a good one,,,, like an engine that runs on beer, or an anti-ice system that converts the hydrogen in the airborne moisture in clouds into a heat source to melt the accumulating ice.... this is how geniuses make life better for the rest of us.....
 
Maybe you would want to scrap the idea of using the MR-16 bulb and use LED's they would work great for taxiing and no heat problems and easier installation.
 
Okay Scott,
How about lights like on my DC-8 (retractable).
Start with a 4 inch square of .040, this will be a door on the bottom of the wing just aft of the main spar. Piano hinged, and operated by a MAC servo, a 75 watt MR16 bulb cut into the door. When retracted, the light shines straight down, when fully extended it illuminates the deer ahead on the runway!:D
Also, as has been tried in a DC-8, they can be used as a last ditch attempt to make a crossing restriction, when thought of as a poor excuse for a speed brake!;)
 
N395V said:
Here ya go, does everything for everybody.
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I like it Milt! Of course, we'd have to repaint the airplane black, and call it the Bluesmobile...:D

But the spririt of inventiveness is cool too. I know my current LL is pretty weak, so the OP's motivation in a good one (my strobes, which I don't like to use on the ground, illuminate things better that the LL...but it is an older install) At work we have retractable LLs inboard near the wing root. It's just a motor, bracket, jackscrew, skin recess fabricatrion and wiring away (ahem)...though its a much smaller % of GW on that aircraft than it would be on an RV! JUst saw Mutha's last post...yes, they would be a good speed brake on an RV too...probably make a nice little rumble too! A cowl mounted LED LL/TL sounds pretty inviting too! Maybe two...one angled ahead (if that makes sense), and one angled a bit down. Starting to get complicated again!

Brantel, the gear fairing is an interesting idea...though it would probably be lights out after my first landing! ;)

Fun to ponder...nice solidworks drawings too!

Cheers,
Bob
 
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I've seen at least one person's design on an RV-3 where he used a solenoid to tilt the single (wing leading edge mounted) landing light between Taxi and Landing positions - great way to "build in lightness" I thought - get two light positions for the weight of one.

One advantage to a center-line landing light is that if there are retro-reflectors on t eh runway/taxiway, you're more likely to see them as the light bounces back in the direction it came from, and wing-tips are too far away from your eyes to get any of that reflected light. We have highway reflectors on the edge of our runway, and th guys with cowling-mounted lights see them great, while those of us with lights out on the wings don't see them at all....

Paul
 
I've not checked this thread in a while and so I was quite surprised to see a bunch more responses added - I thought it had died of natural causes.

Anyway, I've ditched the flap-mounting idea and am working on a servo-adjustable internal wing-tip arrangement, mainly to keep the servo torque requirements down to something manageable.

I'll post some pics when I have achieved what I think will be successful.

...and funny someone should mention engines...

A
 
Keep Inovating

There is lots of cool factor in this idea. Yachts put light under the hull just to light the water at the dock. Small, light LED's that illuminate the ground right under and around the plane at night could be very handy and might let one see the gound coming up on a night landing.

I'm planning to expeirment with the idea when getting to that stage.
 
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